Structural, morphological and electrical transport behaviour of inverse Heusler Mn₂CoSi/n-Si(100) thin film structure

Abstract The family of Co-based Heusler compounds holds considerable promise for spintronic applications due to their theoretically half-metallic magnetic nature. In this work, we have studied the structural, morphological and transport behaviour of Mn 2 CoSi (MCS) inverse Heusler alloy (HA) experimentally in thin film form. Structural analysis has revealed the formation of a cubic structure corresponding to the inverse MCS HA with space group F <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mrow> <mml:mn>4</mml:mn> </mml:mrow> <mml:mo>̅</mml:mo> </mml:mover> </mml:math> 3 m . Fitting results of the x-ray reflectivity (XRR) spectrum indicated that the deposited film is uniform and smooth, with a thickness of 70 nm. Simulation results from Rutherford backscattering spectrometry (RBS) experiments revealed that the film is pure and devoid of foreign elements such as oxygen or nitrogen, with a composition of Mn 2 CoSi. Electrical transport study of MCS thin film structure has been done using the van der Pauw technique, suggesting the ohmic nature of the prepared thin film structure at RT. Moreover, the estimated conductivity, carrier concentration and carrier mobility from Hall measurement are found to be 5361 S cm −1 , 10 21 cm −3 and 25 cm 2 /V.s, respectively which is consistent with the observations reported for half-metallic materials. Surface morphology indicated that the film is smooth, with an average grain size of 38 nm. The possibility of half-metallicity of MCS HA in thin film form makes it a promising candidate for its future applications in silicon-based devices .